The word 'yammer' originates from the Middle English 'yameren', meaning to lament or complain mournfully. It is an echoic or onomatopoeic formation, imitating the sound of persistent, grating speech or wailing. This term is cognate with the Middle High German 'jammer' (lamentation, distress), and both likely stem from a Proto-Germanic root expressing misery or loud complaint. Over time, its meaning softened from intense lamentation to describe the less severe but equally irritating act of talking loudly, whining, or complaining in a nagging, persistent manner.

The word 'yammer' is a simplex word of imitative origin, likely from Middle English 'yameren', which is related to Middle High German 'jammer' (lamentation, misery). Its functional role is as a whole, onomatopoeic verb/noun.